CVE-2006-5853 in Immediacy .NET CMS
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in logon.aspx in Immediacy CMS (Immediacy .NET CMS) 5.2 allows remote attackers to inject arbitrary web script or HTML via the lang parameter, which is returned to the client in a lang cookie.
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Analysis
by VulDB Data Team • 04/27/2026
The CVE-2006-5853 vulnerability represents a classic cross-site scripting flaw within the Immediacy .NET Content Management System version 5.2, specifically affecting the logon.aspx page. This vulnerability stems from inadequate input validation and output encoding mechanisms within the application's authentication handling process. The flaw manifests when the application processes the lang parameter through the login interface, failing to properly sanitize user-supplied input before returning it to the client browser. The vulnerability is particularly concerning as it occurs during the authentication phase, potentially allowing attackers to manipulate session cookies and user experience settings through malicious script injection.
The technical exploitation of this vulnerability follows the standard XSS attack pattern where an attacker crafts malicious input containing script code within the lang parameter. When the vulnerable application processes this input and stores it in a lang cookie, subsequent page requests cause the malicious script to execute within the victim's browser context. This creates a persistent XSS vector that can be leveraged for session hijacking, credential theft, or redirection to malicious sites. The vulnerability maps directly to CWE-79 - Improper Neutralization of Input During Web Page Generation, which specifically addresses the failure to properly encode output before rendering it in web pages. The attack surface is significantly expanded as the vulnerability affects the core login functionality, making it particularly dangerous for authenticated users and administrators.
The operational impact of this vulnerability extends beyond simple script execution, as it compromises the integrity of the authentication system and user sessions. Attackers can potentially steal session cookies, modify user preferences, or redirect authenticated users to phishing sites designed to capture credentials. The vulnerability affects the application's ability to maintain secure user sessions and can lead to unauthorized access to administrative functions. From an ATT&CK perspective, this vulnerability aligns with T1566 - Phishing and T1071.001 - Application Layer Protocol: Web Protocols, as it enables attackers to craft malicious web content that targets user browsers. The persistence of the vulnerability through cookie storage means that even after initial exploitation, the malicious scripts can continue to execute without requiring repeated user interaction.
Mitigation strategies for CVE-2006-5853 should focus on implementing proper input validation and output encoding mechanisms. The application must sanitize all user-supplied input, particularly parameters used in authentication flows, by implementing strict whitelisting of acceptable language codes or by properly encoding any user input before storing it in cookies. Developers should implement Content Security Policy headers to limit script execution and use proper HTTPOnly flags on session cookies to prevent client-side script access. Additionally, the application should validate the lang parameter against a predefined set of supported languages rather than accepting arbitrary input. Organizations should also consider implementing web application firewalls to detect and block suspicious parameter values and ensure regular security updates to address known vulnerabilities. The vulnerability highlights the critical importance of input validation in authentication systems and demonstrates how seemingly minor flaws can have significant security implications for user sessions and system integrity.